Developmental plasticity affects sexual size dimorphism in an anole lizard

While developmental plasticity has been shown to contribute to sexual size dimorphism (SSD) in laboratory studies, its role in shaping SSD variation in wild vertebrate populations is unclear. Here we use a field study and a laboratory experiment to show that resource availability influences the degree of SSD among insular populations of Anolis sagrei lizards in the Bahamas. Total amounts of food biomass explained variation in male, but not female, body size on six Bahamian islands, giving rise to significant differences in SSD. Laboratory experiments on a captive colony of A. sagrei confirmed that variation in SSD was mediated by the effects of prey biomass on developmental plasticity in males, but not females. Indeed, males grew faster and attained larger sizes as adults under high food treatments than under restricted diets, whereas adult females retained similar body sizes under both conditions. Our results indicate that the amount of food available can influence inter-sexual variati...